Path: ...!2.eu.feeder.erje.net!feeder.erje.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Luigi Fortunati Newsgroups: sci.physics.research Subject: Re: Free fall Date: Fri, 15 Mar 2024 01:11:39 PDT Organization: A noiseless patient Spider Lines: 30 Approved: Jonathan Thornburg [remove -color to reply]" References: Reply-To: fortunati.luigi@gmail.com X-Trace: individual.net 0sH2jDDBrMQQFOl8C2ssvQRS504zhol98Q8z5irllBxciQ+Bw0dPUUwSOR Cancel-Lock: sha1:EbmZIf8YYV7RZsYZk1aoD93OyvY= sha256:6a2WT/P/ikmWHgw66AU9DiMRRgBcb9xMjHbTx98l1GI= X-Forwarded-Encrypted: i=2; AJvYcCVvixWRWO6JTiSSyOfVm4YNskTl+AUtkavWki1unmXsJJUYKol0xwb2GaWCErNErBLKtuKB516cH8rEuHt1kyc5C/5nvqCNYaM= X-ICQ: 1931503972 X-Auth-Sender: U2FsdGVkX18dN80T9xuo57mUZYvNUHy0sdjV4MCv6B5mxd+KswyMbPDKMN5xR4vy Bytes: 2466 In free fall, can you go anywhere freely or are there constraints that prevent this? Of course you can't fall straight up and you can't fall sideways. In free fall you can only go in one direction (the vertical one) and in only one versus (downward). The elevator (in free fall) and everything inside it are forced to fall (always) vertically and (always) downwards. So there is a constraint. And, in free fall, can one move in a straight and uniform motion? No, in free fall the motion is always accelerated. The elevator (in free fall) and everything inside it are forced to always accelerate. So there is another constraint. So why call it "free fall" and not "forced fall"? Luigi Fortunati. [[Mod. note -- The "free" in "free fall" means that no non-gravitational forces are acting on the falling body. It's a statement about what forces are (not) acting on the body, not about the uniqueness or non-uniqueness of the resulting motion. -- jt]]